Comparison of the effects of opioid-free anesthesia (OFA) and opioid-based anesthesia (OBA) on postoperative analgesia and intraoperative hemodynamics in patients undergoing spine surgery: A prospective randomized double-blind controlled trial.

Background: Opioids form the basis of perioperative pain management but are associated with multiple side effects. In opioid-free anesthesia (OFA), several non-opioid drugs or neuraxial/regional blocks are used as substitutes for opioids. Ketamine, a N-methyl-d-aspartate antagonist, provides intense analgesia. However, there is a shortage of literature on the effects of ketamine-based OFA on hemodynamics (HD) and postoperative analgesia in patients undergoing thoracolumbar spine surgery.

Materials and methods: This prospective randomized controlled trial included 60 adult patients. The patients in Group OFA (n = 30) received OFA with ketamine and ketofol (1:5) infusion, and those in Group OBA (n = 30) received opioid-based anesthesia (OBA) with fentanyl and propofol infusion. The postoperative pain-free period, pain scores, rescue analgesia, intraoperative HDs, and postoperative complications were assessed.

Results: The mean pain-free period in Group OFA (9.86 ± 1.43 hr) was significantly higher than that in Group OBA (6.93 ± 1.93 hr) (P = 0.002). During the postoperative 48 hours, the total requirement of fentanyl was considerably lower in Group OFA (P < 0.05). There was a significantly higher incidence of hypertension in Group OFA (46%) and hypotension (43%) in Group OBA (43%), respectively. Postoperative nausea vomiting (PONV) was more common in Group OBA at the 2^nd and 6^th hr (P = 0.046 and P = 0.038).

Conclusion: OFA with ketamine and ketofol provided adequate postoperative analgesia with a lower incidence of PONV after spine surgery. However, hypertension in the ketamine group and hypotension in the propofol group required fine titration of the infusion rate of drugs during the intraoperative period.